Blade base



FIG. 1 is a perspective view of a blade base showing our new design;

FIG. 2 is a front side view thereof;

FIG. 3 is a back side view thereof;

FIG. 4 is a first side view thereof;

FIG. 5 is a second side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken line in the drawings depicts unclaimed portion of the blade base only and forms no part of the claimed design. 

CLAIM The ornamental design for a blade base, as shown and described. 